linux-kernel - Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <13521f9f5ebe1cd0a85bf31b5ad5cba0@codeaurora.org>
Date:   Mon, 19 Sep 2016 14:41:10 -0400
From:   bdegraaf@...eaurora.org
To:     Laura Abbott <labbott@...hat.com>
Cc:     catalin.marinas@....com, will.deacon@....com, james.morse@....com,
        mark.rutland@....com, andre.przywara@....com,
        jungseoklee85@...il.com, apinski@...ium.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        timur@...eaurora.org, cov@...eaurora.org
Subject: Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp

On 2016-09-19 14:28, Laura Abbott wrote:
> On 09/19/2016 10:36 AM, Brent DeGraaf wrote:
>> According to section 6.3.8 of the ARM Programmer's Guide, non-temporal
>> loads and stores do not verify that address dependency is met between 
>> a
>> load of an address to a register and a subsequent non-temporal load or
>> store using that address on the executing PE. Therefore, context 
>> switch
>> code and subroutine calls that use non-temporally accessed addresses 
>> as
>> parameters that might depend on a load of an address into an argument
>> register must ensure that ordering requirements are met by introducing
>> a barrier prior to the successive non-temporal access.  Add 
>> appropriate
>> barriers whereever this specific situation comes into play.
>> 
> 
> Was this found by code inspection or is there a (public) exciting test
> case to observe this behavior?
> 
> Thanks,
> Laura
> 

Code inspection only.

Brent